1. Field of the Invention
The invention relates to the field of range finding. More particularly, the invention is a range finder to determine a distance between the user and a single object. More particularly yet, the invention is a range finder for golfers, to determine the distance of a flagstick that marks a particular golf hole.
2. Description of the Prior Art
A golfer uses the same basic swing, typically, for hitting a golf ball any distance, other than putting. Many golfers use ¾, ½, ¼ swings at ranges that are under 75 yards for pitch or chip shots. The golf club size exerts a major influence on how far the golf ball will travel. It is crucial, therefore, that the golfer know the distance to the flagstick or pin, so that he or she may choose the proper combination of club and swing.
Golf range finders are known and are often used by golfers, to determine the distance to the flagstick, also referred to as a pin, that marks the particular golf hole. Some more recently developed golf range finders are digital optical devices with magnifying lenses. The user looks through the device, aligns the digital range marks with the flag pin, and the device indicates the distance to the flagstick. These devices have certain disadvantages. They are bulky and add weight to the already heavy golf equipment; they often require batteries, which run down and need replacing; and they can be quite expensive.
More typically, golf range finders have been provided in the past as look-through cards or plates, with some system of a linear scale or graduated line markings along an aperture, that allows the user to judge the distance of the flagstick or the cup. U.S. Pat. No. 3,409,987 is illustrative of this type of golf range finder. The card has an aperture formed by a base line at the bottom and a distance line at the top that curves upward at one end. Holding the card approximately 24 inches from the eye, the user sights the flagstick and moves the card until the upper and lower ends of the flagstick just fit inside the aperture. The base line has a scale on it, indicating a plurality of positions that represent 10 yard distances. Depending on where along the aperture the flagstick fits between the base line and the distance line, the user can see that the flagstick is 80, 90, 100, . . . 200 yards away and is then able to select the appropriate club.
These cards have a disadvantage in that they have a single aperture with a graduated scale and it is often difficult for the user to determine or to interpolate the distance of the flagstick, or to remember exactly where the flagstick was, once he pulls the card closer, to look at the range information provided on the card.
What is needed, therefore, is a device that is inexpensive to manufacture, small and easy to carry, and that provides a clear, quick, and easy method of determining the distance of a flagstick.